I want to use sidetone using the mobile RingCentral app

I use the RingCentral app on my cell phone, and not on my computer. I have a wired Jabra headset that I use to make calls plugged in with a USB-A connection. When I make calls using my normal cell phone number, I can hear a normal amount of my own voice (sidetone) in the headset. I'm also available to adjust that amount of sidetone using a Jabra app.

However, I can't hear any sidetone when using the RingCentral app. My headset earpieces cover my ear, so I can't hear myself that well when making calls. This results in an uncomfortable conversation and me speaking a lot louder than I want.

Support has not been any help so far. Anybody have any suggestions?